1. Field
The present invention relates to a fuel cell, and more particularly, to a carbon monoxide remover and a reformer used for a fuel cell.
2. Description of the Related Technology
A fuel processor includes a reforming reaction unit and a water gas shift reaction unit. The reforming reaction unit is also referred to as a reformer. The reforming reaction unit is configured to reform fuel into reformed gas containing hydrogen gas. The water gas shift reaction unit is configured to remove undesired gas components other than the hydrogen gas from the reformed gas produced in the reforming reaction unit. The reforming reaction unit needs heat to start a reforming reaction because the reforming reaction using a catalyst is an endothermic reaction. In general, the reforming reaction unit receives heat from an external heat source such as an electric heater using electricity generated by a fuel cell, or a heater using an oxidation catalyst resulting in an exothermic reaction.
In a reformer using methanol as fuel, when methanol and water are reacted in the reforming reaction unit at a constant temperature, hydrogen and carbon dioxide gases are produced by an endothermic reaction, as shown in the following Reaction Equation 1.CH3OH+H2OCO2+3H2  Reaction Equation 1
The products produced in the reforming reaction unit contain an undesired gas such as carbon monoxide. Such carbon monoxide may contaminate a catalyst provided in a stack and reduce the lifespan of the fuel cell. Thus, there is a need to minimize the concentration of carbon monoxide in the reformer. The water gas shift reaction unit serves to lower the concentration of carbon monoxide.